Personal union

A personal union is a relationship of two or more sovereign states, which, through law, share the same person as their head of state.

Personal unions can begin for very different reasons. In many cases a princess who is already married to a king becomes pregnant, and their child inherits the crown of both countries. However, a personal union sometimes was seen as a means against uprisings if a state wants an annexation of an other state. The unions can be written down in a constitution, which clearly expresses that both states shall share the same person as head of state. When that is not the case, a personal union can easily be broken.